Bonjour,
j'ai trouvé sur un forum dell us et je pense avoir la réponse, voir site suivant c'est un bug http://forums.us.dell.com/supportforums/board/message?board.id=dim_monitor&message.id=33721
voici la recette pour une carte nVidia
nVidia Video Cards
If you have an nVidia-based video card, the common issue reported has been the flat panel monitor entering DVI Power Save mode, and that the monitor's DVI input remains in that state. When connected via the VGA input to the VGA output on the video adapter, the video works normally.
The fix for the monitor's DVI Power Save mode problem is shown below. Please read it thoroughly before attempting the fix.
NOTE: If, at any point, you are uncomfortable with the procedure listed below, or you are unsure as to how to perform a certain step, perform up to Step 2 (update your video drivers), as this is critical to preventing the issue from occurring again in the future. Then you may contact Dell's Technical Support department for assistance via email.
You must first request the appropriate DVI Recover file from a Dell Technician via email or by phone at 800-624-9896.
The ZIP file will contain DVI_Recover_FLOPPY.exe and DVI_Recover_CDIMAGE.iso:
If you have a floppy drive, place a blank floppy disk in the floppy drive and run the file DVI_Recover_FLOPPY.exe. This will create a bootable floppy disk. Continue with the steps below.
If you do NOT have a floppy drive, you will need to burn the ISO image DVI_Recover_CDIMAGE.iso onto a CD-R or CD-RW disc. The procedure for this varies from software to software. In most cases, your software will have an option for "Burn Image" or "Write Disc from Image," which you will choose. Ensure the software is looking for .iso files, browse to the location that you extracted the files from the DVI_Recover.zip to, select the file DVI_Recover_CDIMAGE.iso, and complete the image burning process. If your installed software does not have image burning capabilities, the Demo version of Nero 6 may contain that functionality.
IMPORTANT: If you only have a CDROM drive, configure your system to boot from the primary optical drive. See this Dell Knowledge Base for further information.
After you have the bootable floppy disk or CD-R/RW ready, perform the following steps to resolve the problem:
Using the VGA cable provided with your flat panel, connect the monitor to the VGA port on your video card. Ensure that the connection is successful and that you can change the monitor's input to VGA and receive an image.
Download and install the latest nVidia ForceWare drivers here. This will prevent occurrence of the problem once you have used the rest of this procedure to correct it.
If you do NOT have a floppy drive, and are going to be performing the fix using a recordable CD created with the DVI_Recover_CDIMAGE.iso, insert your recorded CD into the primary optical drive now.
Shut down the computer. Disconnect the power cables from both the monitor and the computer.
Disconnect the VGA cable, and reconnect the monitor to the computer via the DVI cable.
Press the power button for both the monitor and computer while unplugged to drain any remaining power.
Re-attach the power cables to both the monitor and the computer.
If you have a floppy drive, insert your bootable floppy into the floppy drive and power on the system. Otherwise, simply power on the system.
The system will boot to the floppy or recordable CD. Wait for approximately one (1) minute. You will not notice any major indicators that the fix is progressing; it is important that you allow the program to attempt to fix the flat panel undisturbed.
Remove the floppy disk or recordable CD, and power down the system.
Power up the system, and test your DVI connection.
If your monitor is still stuck in DVI Power Save mode, boot to the floppy disk or recordable CD again as described above. It may take up to three tries total in order to enact the fix.
If the monitor is still stuck in DVI Power Save mode, the monitor will need to be replaced. Contact Dell Technical Support via email to request a replacement.
With the updated video drivers installed on your system, the fixed (or replacement) flat panel monitor should not experience the problem again.
Retail and/or third-party video card owners should contact the manufacturer of the product (s) in question and request any information on problems seen with LCD flat panel monitors via DVI connections.
je vais leur demander !